Aggregate mixing machine



4 Sheets-Sheet l June 9, 1942- F. l.. cARswL-:LL

AGGREGATE MIXING MACHINE Filed April 17, 1941 June 9, 1942 F. L..cARswELL AGGREGATE MIXING MACHINE Filed April 17, 1941 4 Shex'S-SheerI 2June 9, 1942. F. 1 CARS-WELL 2,285,765

AGGREGATE MIXING IVIACIIIIE' Filed April 17, 1941 4 sheets-sheet 5ATTO'RNEY June 9, 1942- F. 1 cARswELL AGGREGATE MIXING MACHINE FiledApril 17, 1941 4 Sheets-Sheet 4 INVENTOR Ffa/1k L Ca/JWe/K ATTO RN EYPatented June 9, 1942 UNITED STATES PATENT OFFICE AGGREGATE MIXINGMACHINE Frank L. Carswell, Kansas City, Mo.

Application April 17, 1941, Serial No. 388,942

16 Claims.

This invention relates to a mixing machine, for example a machine forcontinuously mixing aggregates and/or ingredients, with bitumen,Portland cement, or other binding medium in the manufacture of pavingand similar materials.

Usually the specifications for such materials require that the variouscomponents be mixed in proportion by weight and since machines of thecharacter described measure the component materials by volume it isdifficult to maintain a continuous run of the product which conforms tothe specifications.

It is, therefore, the principal objects of the invention to provide amachine of this character constructed for continuous movement of thematerials to the mixing point; and to provide the machine with thecontinuous gravimetric feeders whereby continuous streams of therespective materials may be effected to deliver the materials in properproportions by weight.

Other objects of the invention are to provide the machine with means forrecording rate of feed of delivery and any change in weight of thematerials being discharged from their respective hoppers.

A further object of the invention is to provide for automatic levellingof the gravimetric feeders thereby adapting an embodiment of theinvention in a mobile mixing plant.

In accomplishing these and other objects of the invention, ashereinafter pointed out, I have provided improved structure, thepreferred form of which is illustrated in the accompanying drawings,wherein:

Fig. 1 is a longitudinal section through a stationary mixing machineembodying the features of the present invention.

Fig. 2 is a side elevational View of one of the gravimetric feeders.

Fig. 3 is a cross-section on the line 3-3 of Fig. 2.

Fig. 4 is a detail perspective View of the scale beam, poise, and therecorder for indicating weight of the material being discharged througha given period of time.

Fig. 5 is a detail perspective view of the transmission operating thefeed belt and showing the recorder for recording feet of belt deliveryduring a given period of time.

Fig. 6 is a sectional View through the recorder which indicates feet ofbelt delivery over a given period of time.

7 illustrates the recorder for indicating weight of material deliveredper foot of belt travel over a period of time.

Fig. 8 is a wiring diagram of the circuit for stopping feed of thematerials when the supply of one of the materials becomes exhausted.

Fig. 9 is a longitudinal section through a mobile type mixing machineconstructed in accordance with the present invention.

Fig. 10 is a section through the gravimetric feeder of the mobilemachine.

Fig. 11 is a side elevational view of a modified form of the invention.

Fig. l2 is a cross-section on the line I2-I2 of Fig. 11.

Fig. 13 is a similar cross-section on the line I3-I3 of Fig. 11.

Referring more in detail to the drawings:

I designates a stationary type of machine adapted for mixing aggregateswith a bitumen or the like at a central location from which the mixedproduct is conveyed to the place of use. The machine includes astationary base 2, carrying a frame 3 including spaced longitudinals 4and 5. Supported by the frame, above the members 4 and 5, are aggregatecontaining hoppers 6, 'I and 8, having discharge throats 9, I0 and II inthe bottoms thereof through which aggregates are discharged into thegravimetric feeders I2, I3 and I4, later described.

The respective hoppers are charged by an elevator or conveyor I5 whichcarries the materials into a shaker shoe I6, having an upper coarsescreen I'I and a finer mesh, lower screen I8, the shaker being arrangedover the top of the hopper 8 and the upper screen I'I connected with thefeed hopper 6 by a chute I9. The material is discharged from theconveyor onto the upper screen by way of a chute 20 and the particles ofmaterial too large to pass the meshes of the screen I'I slide therealongand are discharged through the chute I9 into the hopper 6. The finermaterials pass through the meshes of the screen I I onto the screen I 8,where the intermediate size particles, or those too large to pass themeshes of the screen I 8, slide down the screen and are discharged intothe hopper 1. The remaining material passes directly through the screenI8 and collects in the hopper 8.

The gravimetric feeders discharge the respective aggregates inpredetermined proportions by weight into a collecting hopper ZI which iscarried by the frame below the hoppers E, 1 and 8. The bottom 22 of thecollecting hopper slopes downwardly toward an elevator pit 23 to receivethe proportioned aggregates for removal from the collecting hopper by aconveyor 24 having discharge into a mixer, for example a pug-mill 25,where the proportioned aggregates are mixed with a liquid, for example abinding material, such as bitumen, the bitumen being discharged into thepug-mill by means f a measuring pump 26 having an outlet 21 discharginginto the path of the material being admitted to the pug-mill.

The mixer has mixing devices 28 to thoroughly mix the materials andarranged to discharge the mixture through an outlet 29 into the trucksor other conveyances used in moving the mixed product to the place ofuse.

The various mechanisms just described are operated from a power unit 30that is carried on the base 2 below the hopper 2|. The power unit hassprockets 3| and 32, the sprocket 3| actuating a chain 33 operating overa sprocket Y34 0n a counter-shaft 35. Fixed on the countershaft 35, indriven relation with the sprocket34, is a sprocket 36, and operatingover the sprocket 36 and a sprocket 31 of the elevator |5 isa chain I 38to form a driving connection for the elevator |5. Each shaker screen isoperated from the elevator by a chain 39 operating over a sprocket 40 ona shaft 4|, having an eccentric 42 which operates the shaker screen by apitman 43. other sprocket 32 on vthe power unit carries a chain 44operating over a sprocket 45 on a speed reducing transmission 46.Operating over suitable sprockets on the driven shaft of thetransmission are endless chains 41, 48, 49 and 50. The

chain 41 extends forwardly of the machine and actuates a counter-shaft5| which carries a sprocket 52 operating a chain 53which runs over asuitable sprocket on a countershaft 54 at the rear of the pug-mill.Fixed on the counter-shaft 54 is a pinion 55 meshing with a gear 56 onthe pug-mill shaft to effect operation of the mixing devices 28 therein.The counter-shaft 54 also drives the measuring pump 26 and the conveyor24 through chains 51 and 58 respectively, the chains operating oversuitable driven sprockets 59 and 60 connected with the respectivemechanisms.

Each of the gravimetric feeders previously mentioned is of the sameconstruction, and a description of one suffices for the others,therefore only one of the feeders will be described in detail.

Supported below the feed throat of each of the respective hoppers is adownwardly sloping feeding tray 6| having sides 62 suspendinglysupported by pairs of links 63 and 64 pivoted to the hopper throats, asat 65, and to the sides of the tray, as at 66, the bottoms 61 of thetrays being spaced from the throats a sufficient distance to allowoscillating movement thereof for promoting discharge of the material, aslater described. Formed in each feed throat, at the sides thereofadjacent the discharge end of the feeding trays, is an outlet opening 68which cooperates with the lower or forward edge of the trays todischarge the material from the hopper. Projecting from the sides of theopening are arms 69 supporting a valve member 10 on a shaft 1| carriedby the arms 69 and actuated from a remote point through a link 12 havingconnection with a crankarm 13 on the shaft 1|. The valve member 10 hasan arcuate valving or gate portion 14 movable over the opening toregulate the effective area thereof so that approximately the desiredamount of material is delivered from the hopper in a continuous stream.

In order to maintain a positive feed of the material from the hopper,the trays 6| are reciprocated by actuating mechanisms 15, as now to Thewith a cam 88 on the shaft 8|.

be described. Each actuating mechanism includes a transmission 16mounted on the crossmembers 11 of the frame to the rear of therespective discharge throats and which is actuated by the chain 48, 49or 50, as the case may be. Fixed on the driven shaft 18 of thetransmission is a pulley 19. Supported above the transmissions,substantially in horizontal alignment with the feeding trays 6| onbracket-like supports 60, are transverse shafts 8|. Fixed on each shaft8| is a pulley 82 which is actuated by a belt 83 operating over thepulley 19. Slidably supported in a bearing 84 carried by eachbracket-like support is a tappet 85, having a foot 86 engageable Locatedin coaxial alignment with the tappet, and in spaced relation therewith,is a rod 89 having connection with the tray 6|. Each tray is normallyretained in a forward position together with its rod 89 by a coil spring90, sleeved on the rod and having one end bearing against the bracket 80and its opposite end against a collar 9| fixed to the rod, Fig. 2. Fixedto the facing ends of each rod 89 and tappet are inclined heads 92 and93, and projectable between the heads is a control wedge 94, the`control wedge being suspendingly supported by a link connected with thescale beam, as later described. It is obvious that when the wedge ispositioned to ll the space between the heads, full movement of thetappets is imparted to the feeding trays through the rods 89 to effectmaximum movement thereof in one direction for return by the springs 90,but as the wedge is withdrawn to leave space between the wedge and therespective heads, the stroke of the feeding tray is reducedproportionate to the spacing since part of the movement of the tappetsis ineffective until the heads of the tappets have moved sufficiently totake up the spaces. Thus by moving the control wedges any predeterminedfeed of material may be maintained from the respective throats of thehoppers, the primary or rough adjustment being made by the valves 10 andthe iineadjustment through the control wedges.

Carried by the longitudinal members 4 and 5 are spaced pairs of scalebeam hangers 96 and 91 forming the fulcrums 98 and 99 for pairs of scalebeams |00 and |0| extending toward each other and having their adjacentends interconnected by links |02, as shown in Fig. 2. One of the scalebeams of each rear pair projects rearwardly along the sides of thehopper throats and carries a balancing poise |03 that is slidablymounted thereon to effect balance of the scales, as later described.Suspendingly supported from the respective scale beams, in spacedrelation with the fulcrum points 98 and 99, are hangers |04 and |05suspending feed belt frames |66 by means of pairs of links |91 and |08.Journalled in the frames |06, at the ends thereof, are shafts |09 and 0.Carried on the respective shafts are pairs of sprockets and ||2 overwhich chains ||3 and ||4 of feeder belts 5 operate. Fixed to each shaft|09, at one end thereof, is a worm gear ||6 meshing with the worm ||1which is connected with a driven shaft H8 of the transmission 16 througha flexible shaft ||9 so that the feed belts are driven at predeterminedspeeds through the transmissions to carry the materials discharged fromthe hoppers therealong for discharge off the ends of the belts into thecollecting hopper 2|. By setting the poises |03 on the scale beams, thescales may be made to balance, and by moving the poises from feedbalancing position the scales will again effect a balance when theweights of the material thereon correspond with the position vof the`poises on the scale beams. Thus as long as the correct amount ofmaterial is carried upon the belts, the scales will balance and maintaina constantly flowing stream of material at a constant feeding rate inaccordance w-ith the weight thereof. However, should the weight vof thematerial on any one of the belts change, the scale for that belt isthrown vout of balance to `cause raising or lowering of the con-trolwedge and increase or decrease the feeding rate of the tray to correctdelivery of the materia-1 and maintain the feed in accordance with theweight of the material.

In order to record the weight of the material being fed and any changethat may 7occur in the flow of material from a specified weight as setby the poises, each poise is connected with a recorder of the charttype, the stylus |2| being operably connected with the .poise through aflexible connection |22 so that should the poise be moved in eitherdirection a corresponding change is indicated on the chart |23 of therecorder by means of a stylus |2|, as shown at |24 in Fig. '7. Therecorder is actuated by a time mechanism (not shown) so that the time ofmaking the weight change is shown on the chart, for eX- ample the chartshown in Fig. 7 indicates that a change in gravimetric feed of thematerial was effected at 2 oclock and that the same rate of i feed wasmaintained after the change up to 4 oclock.

The footage rate of movement of the conveyor is also recorded by meansof a recorder |25 having connection with a driven element |26 on thetransmission and operatively connected with the stylus |21 of therecorder by a connecting mechanism |28, the chart |29 being specificallyillustrated in Fig. 6.

In Fig. 8 is illustrated an electrical circuit for stopping operationvof the feeders l2, `I3 and I4, conveyor 24, and metering pump 26 incase one of the hoppers runs out of material. 'Fixed to the frame of themachine adjacent the poise beam of each scale mechanism is a bracket |30pivotally mounting a mercury switch '|3|, and fixed to each poise beamis a cooperating bracket |32 having inwardly directed fingers |33 and|34 to engage the ends and |36 of a lever carried with the mercuryswitch. The fingers |33 and |34 are located respectively above and belowthe ends of the lever so that when the beam swings downwardly because oflack of material on the belt, the finger |33 lengages the lever to closecircuit through conductors v|3`| and |38 and through connecting wires|39 and |40 to a solenoid switch |4|. The solenoid switch |4'| `openscircuit through conductors |42 and v|43 supplying current to solenoidactuated clutches |44, |45 and |46 for the driving connections -of thetransmissions 16, a solenoid operated clutch |41 for the operating shaftof the conveyor 24, and a solenoid operated clutch |48 for the -drivenshaft of the metering pump. Thus it is obvious that when any one of themercury switches is closed because of lack of material on one of thebelts, operation of all the feeders is suspended, together withoperation of the conveyor 24 and meter pump. The conveyor I5, however,will continue in operation to replenish the hopper which has becomeexhausted of material and the pug-mill will continue to operate to clearitself of the material being mixed. Should for some reason one of thefeeding mechanisms fail to operate, an excessive amount of material maybe delivered onto the feeding belt, in which case the poise beam willswing upwardly and the finger |34 on the beam will tilt the mercuryswitch to close circuit therethrough so that feed of all of the materialwill be stopped until the correctly related feeds are again established.

It is possible that one vof the hoppers may ll to a greater extent thanthe others and to take care of the excess material each hopper isprovid-ed with an overflow opening |49, Fig. 1. If desired the conveyorsmay be provided with revolution counters ||0' operating directly uponthe shafts ||0.

In operation, the poises |03 of the respective scale mechanisms are seton the scale beams to regulate actuation of the feeding trays incooperation with the control valves 14 for maintaining a predeterminedfeed of the aggregates from the respective hoppers according to theweights of the materials being carried in the respective conveyors. Feedof the materials is eected by gravity through the effective areas of thedischarge openings under the influence of the vibrating trays 6|, theextent of Vibration controlling the amount of feed. Should the amount offeed onto one of the belts exceed the specified amount by weight, theincreased weight on the belt effects movement of the scale to change theposition of the beam, which change in position of beam effects acorresponding change in the control wedge to slow down the feed tray forthat particular mechanism. When the feed is such as to again maintainthe balance as set by the counter-poise, the wedge is automaticallyreadjusted to maintain the feed at the desired amount. Should the poisebe moved to change the rate of feed, the fact is recorded on therecorders |20 and should the delivery speed of the feed belts be changedthis is recorded on the charts |29 of the recorders |25, the chartsindicating the time that the change was made and the time the machinewas in operation after such change.

vThe respective aggregates in the proper proportions by weight aredischarged off the ends of the feed belts into the collecting hopper,where they are carried by the conveyor 24 to the pugmill 25 for mixturewith the bitumen and discharged as a finished product through the outlet29.

The mechanism just described is adapted for a stationary plant but in amobile plant where the machine moves up and down the inclines of aroadway, itis necessary to provide a pendulum mounting for therespective gravimetric feeders to maintain the scale mechanisms inhorizontal position at all times regardless of the position of themachine. This is effected by providing a universal connection |50including an outlet socket |5| in the bottom of the hopper and thethroat |52 has a ball-like portion |53 mounted to move within theoutlet. The throat |52 has la depending spout portion carrying brackets|54 and |55 from which the scale beam and conveyor supports aresuspended so that the gravimetric feeder always retains its horizontalposition regardless of the position of the machine. Otherwise themachine operates in the same manner as the stationary plant.

While I have illustrated all the various driving connections as being ofthe chain and sprocket type, it is obvious that other drivingconnections may be used if desired. It is also obvious that in someinstallations the pug-mill may be located directly below the gravimetricfeeders, in which case the conveyor 24 may be omitted.

In the form of the invention illustrated in Fig. 11, the hoppers |60,|6| and |62 discharge onto a common belt type conveyor |63, the belt ofthe conveyor operating over pulleys |64 and |65. 'Ihe upper run |66 ofthe belt receives the material from the hoppers and is'supporteddirectly below the discharge of each hopper on dead rollers |61 and |68so that the belt is supported from yielding movement at these points.However, the belt is free to flex intermediate the dead rollers for therespective hoppers so as to actuate weighing mechanisms |69, |10 and|1|.

Each weighing mechanism includes a scale beam |12 carried on a fulcrum|13 and actuated by a rod |14 slidably mounted in a bearing |15 andhaving a forked upper end |16 carrying rollers |11 and |18 engaging thebottom of the yieldable portions of the belts. The weights of thematerial moving across the yieldable portions of the belt arecounterbalanced by poises |19 operable on the scale end of the beams|12. The scale beams |12 are connected by rods |80 with wedge mechanisms|8| controlling Vibrating trays |82 identical with the trays 6|described in connection with the preferred form of the invention tocooperate with the control valves for regulating feed of material ontothe belt'in accordance with predetermined amounts as set by the poises|19. With this arrangement the scale mechanism |1| measures only thematerial discharged from the hopper |62. The scale |10 weighs thematerial to be discharged from both the hoppers |6| and |62 and thescale mechanism |69 weighs the sum of the material discharged from allof the hoppers, the weight of the material from the preceding hoppersbeing accounted for so that the scales actuate to effect the desiredfeed from the succeeding hoppers.

The end of the belt conveyor discharges directly into the pug-mill |83wherein the various aggregates are mixed with a bituminous materialdischarged from a measuring pump |84, the pump |84 being driven from theconveyor through a belt |85. The conveyor is actuated from the drivenshaft |86 of a transmission |81. The tray operating mechanisms for therespective hoppers are actuated from the power shaft of the transmissionthrough belt connections |88 for the respective hoppers.

Each of the scale beams is provided with a switch mechanism |89 similarto that illustrated in connection with the preferred form of theinvention and which functions to disengage a clutch indicated at |90located between the transmission |81 and the driving motor |9| thereforto stop operation of the feed conveyor and measuring pump whenever oneof the hoppers is not feeding the material at a rate to maintain thedesired feed as set by the scale mechanism.

From the fo-regoing it is obvious that I have provided a machine whereincontinuous streams of aggregates and/or ingredients may be delivered inproportions by weight of the respective materials to a mixer so as toconform with the specications of a specied product.

What I claim and desire to secure by Letters Patent is:

l. A machine for mixing aggregates with a cementing material including,means for separately conveying the respective aggregates in continuousstreams, a gravimetric feeder associated with each conveying means,means controlling said conveying means responsive to actuation of thegravimetric feeders to discharge said aggregates by weight thereof, amixer, means discharging the weighed streams of aggregates to the mixer,and a measuring pump arranged to discharge the cementing material intothe mixer.

2. A machine of the character described including, a supporting frame, aplurality of hoppers carried by the supporting frame and havingdischarge throats in the bottom thereof, control valves for regulatingthe amount of material discharged from the hoppers through said controlvvalves in continuous streams, feed belts for receiving the streams ofdischarged materials, scales supporting the feed belts for measuring thestreams of material discharged thereon, means for actuating the feedbelts, agitating means cooperating with the control valves for assistingin feed of the materials onto said feed belts to maintain apredetermined weight of said streams, means for oscillating saidagitating means, and means controlling the oscillating means responsiveto movement of said scales.

3. A machine of the character described including, a supporting frame, aplurality of hoppers carried by the supporting frame and havingdischarge throats in the bottom thereof, control valves for regulatingthe amount of material discharged from the hoppers through said controlvalves, feed belts for receiving the discharged material, scalessupporting the feed belts and including poises slidable on beams of saidscales for measuring the material carried on said feed belts, means foractuating the feed belts, agitating means cooperating with the controlvalves for assisting in feed of the materials onto said feed belts,means for oscillating said agitating means, means controlling theoscillating means responsive to movement of said scales, and timerecorders connected with the poises for recording position of the poisesover a given period of time.

4. A machine of the character described including, a supporting frame, aplurality of hoppers carried by the supporting frame and havingdischarge throats in the bottom thereof, control valves for regulatingcontinuous streams of material discharged from the hoppers through saidcontrol valves, feed belts for receiving the discharged material, scalessupporting the feed belts for measuring the material discharged thereon,means for actuating the feed belts, agitating means cooperating with thecontrol valves for maintaining a constant predetermined flow of thematerials by weight under control of said scales, means for oscillatingsaid agitating means, means controlling the oscillating means responsiveto movement of said scales, a pug-mill, means for delivering theproportioned materials to the pug-mill, andmeans delivering a mixingliquid to the. pug-mill in a constantly predetermined ow.

5. A machine of the character described including, a supporting frame, aplurality of hoppers carried by the supporting frame and havingdischarge throats in the bottom thereof, control valves for regulatingthe amount of material discharged from the hoppers through said controlvalves, feed belts for receiving the discharged material, scalessupporting the feed belts for measuring the material discharged thereon,means for actuating the feed belts, agitating means cooperating with thecontrol valves for assisting in feed of the materials onto said feedbelts, means for oscillating said agitating means,

means controlling the oscillating means responsive to movement of saidscales, a collecting hopper supported in receiving relation with saidfeed belts, a pug-mill, a conveyor connecting the collecting hopper withthe pug-mill to carry the proportioned materials from the collectinghopper to the pug-mill, means delivering a binding material into thepug-mill, a shaker shoe carried above one of the hoppers and havingscreens arranged to discharge different sized materials into the otherhoppers, and means for conveying a stock material to said shaker shoe.

6. A machine for mixing aggregates with a cementing material including,means for separately conveying the respective aggregates in continuousstreams, a gravimetric feeder associated with each conveying means todischarge said aggregates by weight thereof, a mixer, means dischargingthe weighed streams of aggregates to the mixer, a measuring pumparranged to discharge the cementing material into the mixer, and meansassociated with each feeder and having connection with the other feedersto stop said feed of materials when the weight on any feeder drops belowa predetermined minimum.

'7. A machine for mixing aggregates with a cementing material including,means for separately conveying the respective aggregates in continuousstreams, a gravimetric feeder associated with each conveying means todischarge said aggregates by weight thereof, a mixer, means dischargingthe weighed streams of aggregates to the mixer, a measuring pumparranged to discharge the cementing material into the mixer, and meansassociated with each feeder and having connection with the other feedersand with said measuring pump to stop said feed of materials when theweight on any feeder drops below a predetermined minimum.

8. A portable machine for effecting continuous mix of aggregatesincluding, a hopper containing the aggregates, a mixer, a gravimetricfeeder arranged to feed aggreates from the hopper into the mixer byweight of said aggregates, and universal means suspending thegravimetric feeder from said hopper whereby said gravimetric feeder issupported horizontally regardless of the terrain over which the machineis transported.

9. A machine of the character described including, a supporting frame, aplurality of hcppers carried by the supporting frame and havingdischarge throats in the bottom thereof, control valves for regulatingthe amount of material discharged from the hoppers through said controlvalves in continuous streams, means for receiving the streams ofdischarged materials, scale means for each hopper and arranged tosupport said receiving means for actuation responsive to the weight ofmaterial carried thereby, means for actuating the receiving means tocarry the material thereon, agitating means cooperating with the controlvalves for assisting in feed of materials onto said receiving means,means for oscillating said agitating means, and means controlling theoscillating means responsive to movement of said scale means.

10. A machine of the character described including, a supporting frame,a plurality of hoppers carried by the supporting frame and havingdischarge throats in the bottom thereof, control valves for regulatingthe amount of material discharged from the hoppers in continuousstreams,

a conveyor for receiving the streams of materials discharged throughsaid control valves, scales supporting selected portions of saidconveyor for measuring the material carried thereon, means for actuatingthe conveyor, agitating means cooperating with the control valves forassisting in feed of the material onto the conveyor to maintain apredetermined weight of said materials on the conveyor, means foroscillating said agitating means, and means controlling the oscillatingmeans responsive to movement of the scales.

l1. In an apparatus for effecting continuous mix of a plurality ofmaterials, a mixer, material collecting means arranged to deliver thematerials in continuous movement to the mixer, power actuated feedingmechanisms for effecting continuous feed of each kind of material to thecollecting means, gravimetric means for each power actuated feedingmechanism and arranged to support the material fed thereby to weigh thematerials while in continuous movement, and regulating means connectedwith each gravimetric means and with the associated power actuatedfeeding mechanism, said regulating means being actuated by saidgravimetric means to vary the feed effected by said power actuatedfeeding mechanism.

12. In an apparatus for effecting continuous mix of a plurality ofmaterials, a mixer, a material collecting means arranged to collect anddeliver the materials in continuous movement to the mixer, poweractuated feeding mechanisms for effecting continuous feed of each kindof material to the collecting means, a feed control valve cooperatingwith each power actuated feeding mechanism to feed the materials,gravimetric means for each power actuated feeding mechanism and arrangedto support the material fed thereby to weigh the materials while incontinuous movement, and regulating means connected with eachgravimetric means and with the associated power actuated feedingmechanism, said regulating means being adapted for actuation by saidgravimetric means to vary the feed effected by said power actuatedfeeding mechanism.

13. In an apparatus for effecting continuous mix of a plurality ofmaterials, a mixer, a material collecting means arranged to collect anddeliver the materials in continuous movement to the mixer, poweractuated feeding mechanisms for effecting continuous feed of eachmaterial to the collecting means, a feed control valve cooperating witheach power actuated feeding mechanism, gravimetric means for each poweractuated feeding mechanism and arranged to support the material fedthereby to weigh the continuously moving materials, and regulating meansconnected with each gravimetric means and with the associated feedingmechanism, said regulating means being adapted for actuation by saidgravimetric means to vary the feed effected by said power actuatedfeeding mechanism.

14. A machine of the character described including, a supporting frame,a plurality of discharge throats carried by the supporting frame andrespectively connected with a source of material supply, valve means foreach throat to control volume feed of material from said throats incontinuous streams, continuous conveying means carried by the supportingframe and movable under the discharge throats for receiving the streamsof material thereon, scale feeding means associated With each throat andarranged in supporting relation with said conveying means and beingadaptedrfor actuation responsive to fluctuation in weight of materialbeing carried upon said conveying means, power actuated meanscooperating with each valve means for assisting in feed of saidmaterials onto the conveying means, and regulating means havingconnection with one of said feeding means for each discharge throat andthe associated scale for varying feed of the materials while thematerials are under continuous movement by said conveying means.

15. A machine for mixing aggregates and a cementing material including amixer, a metering pump for discharging the cementing material into themixer, a plurality of discharge throats respectively connected with acontinuous source of aggregate supply, valve means for each throat tocontrol the material discharged through said throats in continuousstreams, continuous conveying means movable under the discharge throatsfor receiving the aggregates discharged therefrom, scale meansassociated With each throat and arranged to support said conveying meansfor actuation responsive to Weight of material carried upon saidconveying means, agitating feeding means cooperating with each valvemeans for assisting in feed of said materials onto the conveying means,means for oscillating said agitating means, and means regulating saidagitating feeding means responsive to movement of the associated scalesfor varying feed of the materials while the materials are un'- der`continuous movement by said conveying means to the mixer.

16. A machine of the character described including, a plurality ofseparate material supply means, a plurality of discharge throatsrespectively oonnected with the separate material supply means, meansfor each throat to. control the amount of material discharged throughsaid throats in continuous streams, a continuous conveying means movableunder the discharge throats for receiving the materials dischargedtherefrom in continuous streams, scale means associated with each throatand arranged to support said conveying means for Weight of materialcarried upon said conveying means, each succeeding scale means beingarranged for weighingthe material weighed by a preceding scale meansandrin addition the material discharged from its related dischargethroat, regulating means for said control means, and an actuatingconnection between each control means and its related scale means forvarying feed of materials While the materials are under continuousmovement by said conveying means.

FRANK L. CARSVVELL.

